Nonlocal Potentials in Independent-Electron Models

This article summarizes the motivation for extending current density functional theory to include nonlocal one-electron potentials and proposes methodology for practical calculations. The theoretical model, orbital functional theory, has been shown to be exact in principle for the general N-electron problem but must depend in practice on a parameterized correlation energy functional, The discussion here is intended to honor Lee Alien and bring up to date some conversations that we began in 1954. © 2003 Wiley Periodicals, Inc.